You can use 3DOF but it's a bit convoluted. You need to get the data from EDTracker into opentracks joystick input plugin. But ED's axis range is too big or something so it doesn't work directly.
So what you have to do is use joystick curves utility to read EDtrackers data. Enable preserve axis range. Then joystick curves outputs to Vjoy which the opentrack joystick plugin does recognize. Then you can use EDtracker with 3DOF in any TrackIR compatible game.
In time there will probably be native support for EDtracker, or someone might make the Edtracker range more directly compatible. One of the opentrack devs said he might eventually do it.
I have the config/ini files for joystick curves and opentrack that will let you use EDtracker with 3DOF here.
A more direct solution would be much better and more efficient than this convoluted solution of course.
You're better off using Hatire if you are using facetracknoir/opentrack so you get the raw values for all three axis.